结构化LDPC码的改进比特翻转译码算法

Improved Bit-Flipping Method for Decoding Structured Low-Density Parity-Check Codes

为提高结构化低密度奇偶校验码的硬判决比特翻转译码算法的性能,提出了一种极低复杂度的改进比特翻转译码算法.该算法利用信道输出序列的幅度将硬判决比特分成两组,在每轮迭代中,利用两个译码门限对多个比特进行翻转,降低了每次翻转比特时发生错误的概率,在加快译码收敛速度的同时实现了译码性能的提高;并且该算法仅在迭代前需要实数运算,而在每轮迭代中只需逻辑运算即可,复杂度极低.仿真结果表明,该算法以极低的复杂度获得了较快的译码收敛速度和优异的译码性能.

An improved bit-flipping （BF） algorithm with low complexity for decoding structured low-den- sity parity-check codes （LDPC） is proposed to improve the performance of the hard-decision BF algo- rithm. The hard-decision bits are divided into two groups based on the magnitudes of the received sym- bols, and at each iteration, the proposed algorithm can flip more than one bit with using two thresholds, and the flipping error probability is effectively decreased. The improved BF algorithm requires some real number comparisons before iterations and requires only logical operations during the iterations. Compared with the weighted bit-flipping algorithm and its modifications, the new method is with significantly lower complexity. Simulations show that the proposed algorithm is provided with very fast convergence speed and excellent performance with significantly low complexity.